Tailoring Crystalline States of Alloy Coating for High Current Density and Large Areal Capacity of Zn

Abstract Due to issues of hydrogen evolution, corrosion, and uncontrolled deposition behaviors at the Zn anode, the practical implementation of Zn‐ion batteries has faced significant obstacles. Very limited attention is directed toward various alloy crystalline states for the Zn anode protection primarily due to the challenge of synthesizing high‐quality alloy coatings with diverse crystalline states. In this study, the crystalline state of NiCr alloy coating is precisely manipulated using magnetron sputtering, revealing distinct thermodynamic and kinetic changes induced by variation in the crystalline state. This research emphasizes the fundamental understanding of microstructure dynamics and achieves a highly reversible Zn anode at harsh conditions of high current density (80 mA cm −2 ) and large areal capacity (40 mAh cm −2 ), thus enabling high‐capacity and longevous pouch battery.